JP4394207B2 - Wheel assembly - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to automotive suspensions, and more particularly to an assembly for dampening vertical vibrations of a wheel assembly.
[0002]
[Prior art]
For prior art, see U.S. Pat. No. 4,991,698.
[0003]
[Problems to be solved by the invention]
An important object of the present invention is to provide an improved suspension for automobiles.
[0004]
[Means for Solving the Problems]
In accordance with the present invention, a vehicle wheel assembly is disposed within an annular region to damp vertical vibrations of the wheel axis, a brake assembly that defines an outer radius of the annular region about the axis, and the wheel assembly. Including a damped mass assembly.
[0005]
In accordance with another feature of the invention, a vehicle wheel assembly includes a wheel axis, an annular region about the axis, a brake assembly within the annular region, and an annular region for dampening vertical vibrations of the wheel assembly. A damping mass assembly disposed therein. The damping mass assembly includes a damping mass and a damping mass vertical positioning assembly for positioning the damping mass. A vertical positioning assembly for positioning the damping mass includes a shaft that converts vertical vibrations of the wheel assembly into a vertical non-rotating movement of the damping mass, and a first for resisting the vertical movement of the damping mass in a first direction. Includes one spring.
[0006]
Other features, objects, and advantages will become apparent from the following detailed description, taken in conjunction with the accompanying drawings.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Referring now specifically to FIG. 1 of the accompanying drawings, which shows an active suspension assembly according to the present invention. The wheel assembly 10 includes an axis formed by the axle 37, a tire 12, a hub 14, and a brake element. The brake element includes a brake disc 18 and a brake pad 16. A mass damper assembly 19 is positioned in an annular region having an outer diameter defined entirely by the outer periphery of the brake element (brake pad 16 and brake disc 18). The mass damper assembly 19 includes a damping mass 20 and a vertical positioning assembly 24 having a central shaft 28, an orifice plate 30, vertical positioning springs 32 and 34 disposed within a hollow cylinder 26 of the damping mass 20. An actuator 36 connects the wheel assembly 10 to the body subframe. Both of these are shown in this figure. In this embodiment, the mass damper assembly 19 includes a second vertical positioning assembly. The second vertical positioning assembly is not shown in this figure.
[0008]
The elements of the mass damper assembly damp vertical vibrations of the wheel assembly. This will be described in more detail below. Actuator 36 as described in U.S. Pat. No. 4,981,309 acts against the upward and downward movement of the wheel assembly, thereby eliminating the vertical movement caused by road irregularities from the body. Isolate the subframe, and thus the car compartment. Furthermore, the actuator 36 cooperates with a similar actuator provided on the other wheel to control the characteristics of the passenger compartment.
[0009]
Reference is now made to FIG. 2, which shows a partial cross-sectional schematic view of mass damper assembly 19. The mass damper assembly 19 includes a damping mass 20 and two vertical positioning assemblies 24a, 24b. These positioning assemblies include central shafts 26a and 26b, vertical positioning springs 28a, 30a, 28b, and 30b, orifice plates 60a and 60b, and fluid-filled cylinders 70a and 70b. A slot 38 extends horizontally through the damping mass 20 along an axis parallel to the tire rotation axis so that the axle 37 can move in a direction perpendicular to the damping mass 20. The hollow cylinders 27a and 27b penetrate the damping mass 20 in the vertical direction.
[0010]
The shafts 26a, 26b are securely attached at each end to the non-rotating part of the wheel. The shafts 26a and 26b extend in the vertical direction through the cylinders 27a and 27b. The orifice plates 60a and 60b are firmly attached to the shaft at a substantially vertical center position of the damping mass 20. End caps 44a, 44b, 46a, 46b are securely attached to the damping mass 20 at the ends of the cylinders 27a, 27b. The vertical positioning springs 28a, 30a, 28b, and 30b press the damping mass 20 against the axle 37 toward the vertical center position. In one embodiment, the outer diameter of springs 28a, 30a, 28b, and 30b is approximately equal to the diameter of cylinders 27a and 27b.
[0011]
In one embodiment of the invention, the vertical positioning springs 28a, 30a, 28b, and 30b are not attached to either the end plate, the orifice plate, or the shaft at either end. That is, these positioning springs are “floating” and not pre-compressed. The elements of the vertical positioning assemblies 24a, 24b may be dimensioned, formed and configured so that only one of the springs 28a and 30b exerts a force at any one time. In addition, the elements of the vertical positioning assemblies 24a, 24b are dimensioned, formed and configured so that the vertical positioning springs 28a, 30a, 28b and 30b only exert a force in the compressed state. It is good to be. This is advantageous because it allows vertical positioning with a relatively short spring. Since the mass damper assembly 19 can be reduced in size by shortening the spring, both the brake and the mass damper assembly 19 can be arranged on the wheel.
[0012]
Fluids such as hydraulic oil may be placed in the sealed portions 70a and 70b of the cylinders 27a and 27b between the end plates 44a and 46a and 44b and 46b. The damping mass 20 can be moved up and down with respect to the shafts 26a and 26b by a bearing (not shown) provided on the end cap, and at this time, the fluid is held in the seal portions 70a and 70b by the seal.
[0013]
In the configuration of FIG. 2, the force is exerted by the spring when the spring is compressed. When the damping mass 20 moves downward, the upper spring 28a is compressed between the end cap 44a and the orifice plate 60a, and the upper spring 28b is compressed between the end cap 44b and the orifice plate 60b, and these upper springs 28a. And 28b apply a force upward on each of the end caps 44a and 44b, thereby pushing the damping mass 20 upward toward the horizontal center position. Similarly, as the damping mass 20 moves upward, the springs 30a and 30b are compressed, which causes the springs to exert a force downward on the end caps 46a and 46b, thereby moving the damping mass 20 toward the horizontal center position. Press down. Since neither end of the spring is attached, the springs 28a, 28b, 30a, 30b exert a force in the compressed state but not in the tensioned state. The upper springs 28a and 28b do not resist or encourage the upward movement of the damping mass 20, and the lower springs 30a and 30b prompt the movement of the damping mass 20 against the downward movement. There is nothing.
[0014]
Fluid cylinders 27a and 27b act as part of damping mass 20, which also resists vertical movement of damping mass 20 relative to shafts 26a, 26b and dissipates vertical vibration energy.
[0015]
The vertical movement of the damping mass 20 causes fluid to pass through the orifices 72 of the orifice plates 60a and 60b. These orifices are sized so that they resist the flow of fluid and thereby attenuate the vertical movement of the damping mass. Orifice plates 60a and 60b are configured and configured so that they exert the appropriate resistance at all speeds encountered by the mass damper assembly. Orifices are discussed below in FIGS. 3-6c and corresponding portions of the present disclosure.
[0016]
In one embodiment of the invention, the damping mass assembly has a damping mass 19 having a mass about half that of the wheel assembly, a spring constant of 48.22 kg / cm 2 (270 pounds per inch), The elasticity is 285.73 kg / cm (1600 pounds per inch).
[0017]
The damping mass assembly according to the present invention is advantageous because the size of the damping mass assembly can be made sufficiently small using conventional materials and the brake element can be placed in the wheel.
[0018]
Referring to FIG. 3, a more detailed perspective view of the orifice plate 60a is shown. The orifice plate 60a has a circular outline as a whole and is fitted to the inner shaft 26a. The orifice plate has two generally circular faces, one of which is shown in this figure. The orifice 72 allows fluid to pass through the orifice plate 60a. In this figure, two additional orifices are obscured by a flapper 80 attached to surface 79. The attachment hole 75 is a hole for attaching a flapper (not visible in this figure) similar to the flapper 80 to a surface opposite to the surface 79. In operation, the mounting hole 75 is plugged with screws or other fasteners (not shown) so that there is no fluid flow through the mounting hole 75. The low speed holes 94 and 96 will be described below. A stop 100 (shown in phantom) may be mounted on the flapper 80, which is illustrated below in FIG. 4, which shows a top view of the flapper 80. In one embodiment, the flapper 80 is comprised of spring steel having a thickness of 0.56 mm (0.022 inches) and has a central section 84 with a mounting hole 82. The mounting hole 82 is aligned with the mounting hole 75 in the orifice plate to accept a mounting screw or other fastener. Arms 86, 88 extend from the central section 84. At the tips of these arms 86, 88 are circular flapping sections 90, 92 having a radius of about 12.7 mm (0.500 inches) slightly larger than the orifice 72 of FIG. The flapper 80 is positioned so that the central section is securely attached to the orifice plate and the flapping section can be freely deflected away from the orifice plate, as described in more detail below. The flapper 80 has low speed holes 94, 96 in each flapping section 90, 92 concentric with the circular flapping section. In one embodiment, the radius of the low speed hole is about 0.167 inches.
[0019]
Referring to FIG. 5, there is shown a plan view of one orifice plate 60a with a flapper 80 in place. A central hole in the orifice plate receives the shaft 26a or 26b. The four orifices 72 have a diameter of about 0.467 inches and allow fluid to pass through the orifice plate 60a. The flapper 80 is positioned such that the orifice 72 is covered by the sections 90, 92. A second flapper (not shown in this figure) may be positioned on the opposite surface of the orifice plate 60a.
[0020]
Referring to FIGS. 6A, 6B, and 6C, there are shown partial cross-sectional views of the orifice plate 60a, illustrating the operation of the flapper 80. During slow movement of the fluid in the direction indicated by arrow 96, the fluid flows through the central hole 94 as shown in FIG. 6A, so the effective area of each orifice 72 is the area of the hole 94. The force acting on the flapping section 90 during high speed movement of the fluid is sufficient to deflect the flapping section 90 away from the orifice plate, as shown in FIG. In addition to flowing through the hole 94, it also flows through a region 98 that is deflected away from the orifice plate 60A, thereby increasing the effective area of the orifice 72. If the fluid flow rate is higher, as shown in FIG. 6C, the force acting on the flapping section 90 is not limited by flow by the flapping section 90, and the effective area is essentially the area of the orifice. Is sufficient to deflect the flapping section 90 far enough away from the orifice plate 60a as limited by an orifice 72 equal to. Even if the flapping section 90 is deviated further, the effective area of the orifice 72 does not increase, and the flapping section 90 is deformed. A stop 100 may be provided to prevent the flapping section 90 from being excessively deflected.
[0021]
Other embodiments are in the claims.
[Brief description of the drawings]
FIG. 1 is a partial sectional view of a wheel assembly and a suspension system according to the present invention.
FIG. 2 is a cross-sectional view of a damping mass assembly according to the present invention.
FIG. 3 is a perspective view of an orifice plate according to the present invention.
FIG. 4 is a plan view of the flapper.
5 is a plan view of the orifice plate of FIG. 3 with the flapper of FIG. 4 in place.
6 is a cross-sectional side view of the orifice plate of FIG. 5 illustrating the operation of the flapper.
[Explanation of symbols]
10 Wheel assembly 12 Tire 14 Hub 16 Brake pad 18 Brake disk 19 Mass damper assembly 20 Damping mass 24 Vertical positioning assembly 26 Hollow cylinder 28 Central shaft 30 Orifice plates 32, 34 Vertical positioning spring 36 Actuator 37 Axle

Claims (5)

A wheel assembly for a vehicle,
Wheels,
A wheel axle (37),
A brake assembly (16, 18) defining an outer diameter of an annular region centered on the wheel axle (37);
A damping mass assembly (19) including a damping mass (20) to damp vertical vibrations of the wheel assembly;
In the wheel assembly for a vehicle comprising:
The damping mass assembly is disposed in the annular region and further comprises a damping mass vertical positioning assembly (24a, 24b) for positioning the damping mass (20);
The damping mass vertical positioning assembly comprises:
Cylinders (27a, 27b) disposed in the damping mass (20) and filled with liquid;
A first spring (28a, 28b) disposed in the cylinder filled with liquid, the damping mass (20) moving vertically towards the first direction only when in a compressed state A first spring (28a, 28b) that resists,
A second spring (30a, 30b) disposed in the cylinder filled with liquid, the damping mass (20) being in the opposite direction of the first direction only when in a compressed state A second spring (30a, 30b) that resists vertical movement toward the second direction;
A motion damper that includes a shaft (26a, 26b) in the damping mass and damps vertical movement of the damping mass;
An orifice plate (60a, 60b) provided between the first spring and the second spring and on the shaft in the cylinder, which is generated when the wheel assembly vibrates vertically. The orifice plate (60a, 60b) through which the liquid in the orifice plate flows when the wheel assembly moves vertically to resist vertical movement of the damping mass;
A wheel assembly comprising:   The wheel assembly (10) according to claim 1, wherein the motion damper comprises a size adjuster (90, 92) for changing the effective diameter of the orifice in accordance with the flow velocity. The size adjuster includes a flapper (80) that changes the orifice (72);
The wheel assembly (10) according to claim 2, wherein the flap is deflected such that the flapper leaves the orifice.   The wheel assembly (10) of claim 3, wherein the flapper (80) has a hole (94, 96) therethrough. The wheel assembly includes a second cylinder (27b) disposed in the damping mass and filled with liquid;
The second cylinder is
A first spring (28b) disposed in the cylinder filled with liquid, the damping mass (20) moving vertically towards the first direction only when in a compressed state A first spring (28b) that resists
A second spring (30b) disposed in the cylinder filled with liquid, wherein the damping mass (20) is in a direction opposite to the first direction only when in a compressed state; A second spring (30b) that resists vertical movement in the direction of
A motion damper comprising the shaft (26a, 26b) in the damping mass, and dampening vertical movement of the damping mass;
An orifice plate (60a, 60b) provided between the first spring and the second spring and on the shaft in the cylinder, which is generated when the wheel assembly vibrates vertically. The orifice plate (60a, 60b) through which the liquid in the orifice plate flows when the wheel assembly moves vertically to resist vertical movement of the damping mass;
The wheel assembly according to any one of claims 1 to 4, further comprising:

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